15. The effects of trametinib on the developing human fetus are unknown. For this reason and because MEK inhibitors as well as GSK2141795 are known to be teratogenic, women of child-bearing potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Women of child-bearing potential must have a negative serum pregnancy test within 14 days prior to randomization. Should a woman become pregnant or suspect she is pregnant while she is participating in this study, she should inform her treating physician immediately.